A need exists to prepare better composite materials including nanostructured composite materials. For example, many energy applications such as capacitors and batteries require better performance of materials. Nanostructured materials provide the ability to engineer important properties such as surface area and electrical charge transport.
An important class of material is highly porous material which provides high surface area. For example, carbon aerogels (CAs) are a unique class of porous materials that are being commercialized and hold technological promise for a variety of applications, including catalysis, adsorption and energy storage.[1] The utility of these materials is derived, at least in part, from their high surface areas, electrically conductive frameworks, and tunable porosities. To expand the applications for these materials, efforts have focused on the incorporation of modifiers, such as carbon nanotubes (CNTs) or metal nanoparticles, into the carbon framework that can potentially enhance the thermal, electrical, mechanical, or catalytic properties of the aerogel.[2] For example, a new class of ultra low-density CNT-CA composites was recently reported that exhibit both high electrical conductivity and robust mechanical properties.[3] These CA composites are believed to be among the stiffest low-density solids reported and exhibit elastic behavior to compressive strains as large as about 80%. In these materials, however, the CNTs are embedded within the skeletal network of the CA and, as a result, the accessible surface area associated with the nanotubes is minimal. While this structural motif does serve to enhance the bulk electrical and mechanical properties of these low-density materials, a need exists for many applications to design CA composites that provide functional access to the surfaces of the CNTs. Other types of composite materials comprising nanomaterials such as nanowires and nanotubes are needed, particularly materials having macroscopic dimensions but nanostructured elements.